There is a question that has occupied physicists, philosophers, and theologians for centuries, one that became newly scientific in the twentieth century when cosmologists first established that the universe had a beginning. The question is this: what came before?

For most of human history, that question was answered through mythology or metaphysics. The universe either existed eternally, cycling through infinite time, or it was created ex nihilo by a divine act. Modern cosmology displaced both answers without quite replacing them, giving scientists a detailed picture of the first fractions of a second after the Big Bang while leaving the moment of origin itself, and everything that might have preceded it, in a fog of theoretical uncertainty.

In the latest episode of NHPR’s “Cosmically Curious,” Saint Anselm College physicist Nicole Gugliucci takes on this question directly, offering listeners a guided tour of what physics can and cannot say about the universe’s origins. The episode aired May 22 and represents one of the most philosophically rich installments yet of a program that has become one of New Hampshire public radio’s most consistently compelling science offerings since its March 2026 launch.

The Problem with Asking “Before”

The central challenge in discussing what preceded the Big Bang is not just a lack of data. It is a deeper conceptual problem: the Big Bang, as physicists understand it, did not just create matter and energy. It created time itself.

If time began with the Big Bang, then asking what happened “before” the Big Bang is like asking what is north of the North Pole. The question uses a grammatical structure, “before,” that implies the existence of a temporal sequence, but it refers to a state in which that sequence did not exist. The question is not unanswerable because the data is missing. It is potentially unanswerable because the conceptual framework required to answer it may not yet exist.

Gugliucci, who has spent her career at the intersection of astronomy education and public communication, is skilled at helping non-specialist audiences grasp exactly this kind of conceptual difficulty without losing them in jargon. As she explains it, the universe’s expansion, the fact that galaxies are generally moving away from one another, is the key observational fact. Run that expansion backward through time and everything in the observable universe converges on a single point of extraordinary density and temperature. That convergence point is the Big Bang: not an explosion in space but an explosion of space itself.

The implication is that space and time, the very container in which physical events occur, came into existence at that moment. Before the Big Bang, there was no “where” for anything to be and no “when” for anything to happen.

Two Physics That Don’t Speak the Same Language

Understanding the earliest moments of the universe, and any speculation about what preceded it, requires combining two of the most successful and most frustrating theories in all of science. They are also theories that currently refuse to be unified.

Einstein’s general relativity describes how gravity works at cosmic scales, explaining the large-scale structure of the universe, the behavior of black holes, and the expansion of space with extraordinary precision. Quantum mechanics, developed in the early twentieth century, describes how particles and fields behave at subatomic scales, explaining chemistry, electronics, and nuclear physics with equal precision.

The problem is that these two theories are fundamentally incompatible at a mathematical level. Each works brilliantly in its own domain. But when both are needed simultaneously, as they are in the extreme conditions of the Big Bang, where the entire universe was compressed to quantum scales and gravity was as intense as it gets, the equations break down. They produce infinities, nonsensical results that signal the limits of the current theoretical framework.

The holy grail of theoretical physics is a single unified theory, often called quantum gravity, that merges general relativity and quantum mechanics into a coherent description of nature at all scales. String theory and loop quantum cosmology are two of the most developed attempts to build such a theory. Neither has been experimentally confirmed.

Until quantum gravity exists, the universe’s earliest moments remain beyond the reach of physics, not because the observations are impossible but because the theoretical tools to interpret them have not yet been built. Gugliucci’s gift as an educator is her ability to make this fundamental limitation feel not like a defeat but like a genuine invitation: the universe has more to teach us, and the teaching is not yet complete.

What Theoretical Models Suggest

Despite the lack of a confirmed theory, physicists have not stopped speculating, and some of those speculations have developed into serious theoretical frameworks with mathematical rigor and testable predictions.

One class of proposals involves what cosmologists call eternal inflation. In the standard inflationary model of cosmology, the early universe underwent a brief period of exponential expansion, stretching from a subatomic scale to cosmic size in a tiny fraction of a second. This inflation explains several observed features of the universe, including its remarkable uniformity and the specific pattern of temperature fluctuations in the cosmic microwave background, the faint afterglow of radiation left over from the early universe.

In eternal inflation, this exponential expansion never fully stops. Different regions of the inflating space transition out of the inflationary state at different times, each producing what looks from the inside like its own Big Bang and its own observable universe. In this framework, our universe is one bubble in an infinite sea of bubbles, a multiverse in which the Big Bang was not the beginning of everything but the beginning of our particular pocket of existence.

The eternal inflation model has the appealing feature that it does not require the universe to have a beginning. The inflating background state may have always existed, with bubble universes periodically condensing out of it. But eternal inflation also faces deep challenges: it is difficult to extract testable predictions from it, and some physicists argue that it is not even a scientific theory in the proper sense because it cannot be falsified.

Cyclic cosmologies offer a different approach, one that echoes ancient mythological traditions of eternal recurrence. In these models, the universe undergoes repeated cycles of expansion and contraction, with each Big Bang representing not an absolute beginning but the start of a new cycle following the end of the previous one. Theorists including Paul Steinhardt and Neil Turok have developed sophisticated cyclic models using string theory’s concept of extra dimensions, imagining our universe as a membrane that periodically collides with another membrane in a higher-dimensional space.

Loop quantum cosmology, which applies the mathematical techniques of loop quantum gravity to the early universe, suggests a different possibility: that the singularity at the Big Bang, the mathematical infinity that marks the breakdown of general relativity, is replaced by a quantum bounce. In this picture, the universe may have contracted to an extremely dense but finite state before bouncing outward in what we call the Big Bang. What lies before the bounce, in this model, is a previous universe collapsing to its most concentrated state.

Why New Hampshire Has a Stake in This Conversation

The question of cosmic origins might seem remote from the everyday concerns of New Hampshire residents, but the state has genuine connections to the science. Saint Anselm College, where Gugliucci teaches, is one of the few liberal arts institutions in the country with a strong commitment to integrating rigorous science education into a humanities-centered curriculum. The college’s approach to physics education reflects a conviction that scientific literacy, including an understanding of the deepest questions physics is trying to answer, is part of what it means to be an educated person.

Gugliucci herself embodies that commitment. Her outreach work, including her contributions to the Cosmically Curious series that NHPR launched in March 2026, is rooted in the belief that the public deserves access to genuine scientific conversation, not just simplified summaries. When she discusses the breakdown of classical physics at quantum scales, or explains why the word “before” becomes conceptually problematic when applied to the Big Bang, she is treating her audience as intelligent adults capable of engaging with difficulty rather than needing it to be removed.

The University of New Hampshire has its own connections to this kind of fundamental science. UNH researchers have contributed to projects studying the cosmic microwave background and the large-scale structure of the universe, and the state’s academic community participates in the broader scientific infrastructure through which these questions are slowly becoming answerable.

The Telescope at the Edge of Knowing

One of the most remarkable developments in recent years for the study of cosmic origins is the James Webb Space Telescope. Launched in December 2021 and reaching full operation in 2022, Webb has been providing unprecedented observations of the early universe, seeing galaxies that formed within the first few hundred million years after the Big Bang. These observations have already produced surprises: some early galaxies are larger and more developed than the standard cosmological model predicted, hinting that the very early universe may have had dynamics that current models do not fully capture.

Webb cannot see before the Big Bang. No telescope ever could, because the universe was opaque to light during its first 380,000 years: the plasma was too dense for photons to travel freely. The cosmic microwave background represents the earliest light we can ever directly observe, a snapshot of the universe when it first became transparent. What came before that, in the first moments of the Big Bang, and what came before the Big Bang itself, will have to be inferred from theoretical understanding rather than direct observation.

But the surprises that Webb keeps producing serve as a reminder that the universe is under no obligation to match our current theories. The most productive scientific stance toward the question of what came before the Big Bang may not be a confident assertion that the question is unanswerable, but a careful openness to the possibility that future theoretical breakthroughs will reframe the question in ways we cannot currently anticipate.

For New Hampshire listeners who want to follow this conversation as it develops, NHPR’s Cosmically Curious series has been building a body of accessible cosmological content since its launch. Earlier episodes have explored topics from the science of warp drives and faster-than-light travel to the chemistry of rocket fuel and the physics of Mars missions, each one drawing on the expertise of researchers at New Hampshire’s colleges and universities.

The question of what came before the Big Bang is not likely to be resolved soon. But the conversation Gugliucci is inviting on NHPR, with its clear-eyed acknowledgment of what is known, what is unknown, and what may be permanently unknowable with current tools, is exactly the kind of scientific communication that makes the universe’s mysteries feel like an invitation rather than a dead end.

What came before the Big Bang?

Physics currently cannot answer this question with certainty. The Big Bang created both space and time, which means the concept of "before" may not apply in the conventional sense. Theoretical frameworks including eternal inflation, cyclic cosmology, and loop quantum cosmology each propose different possibilities, but none has been experimentally confirmed. A unified theory of quantum gravity, merging general relativity and quantum mechanics, is needed before this question can be rigorously addressed.

Who is Nicole Gugliucci and what does she teach at Saint Anselm College?

Nicole Gugliucci is an associate professor of physics at Saint Anselm College in Manchester, New Hampshire. She specializes in astronomy and physics education and is a contributor to NHPR's Cosmically Curious series, which launched in March 2026 and explores scientific topics for general audiences.

What is NHPR's Cosmically Curious program?

Cosmically Curious is a science podcast and radio series produced by New Hampshire Public Radio that launched in March 2026. The program features conversations with researchers from New Hampshire's colleges and universities about topics in astronomy, cosmology, and physics. Episodes have covered subjects including warp drives, rocket fuel chemistry, and the origins of the universe.

What is the cosmic microwave background and why does it matter?

The cosmic microwave background is faint thermal radiation that permeates the entire universe, first detected in 1965. It represents light from approximately 380,000 years after the Big Bang, when the universe first became transparent to photons. It is the earliest direct observational evidence we have of the early universe and has been mapped in extraordinary detail by satellites including WMAP and Planck, providing strong support for the Big Bang model.

What is the difference between general relativity and quantum mechanics?

General relativity, developed by Albert Einstein in 1915, describes gravity and the large-scale structure of the universe. Quantum mechanics describes the behavior of particles and fields at subatomic scales. Both theories are extraordinarily successful in their respective domains, but they are mathematically incompatible with each other. Reconciling them into a unified theory of quantum gravity is one of the central unsolved problems in theoretical physics.

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